While persisting(merge) an entity, I try to update a date column with a null value. This is not happening and the old value is only retained. I'm using EJB 3.0 with JPA. How do I update my date columns with null?
How (exactly) are you setting the date to null and merging the object? What JPA provider are you using?
Check the managed object after the merge and confirm that its date has been set to null. Also if the date was null to begin with, nothing may need to be updated. Can you update other attributes of the object? Do any errors occur?